© Edwards Limited 2014. All rights reserved.
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Edwards and the Edwards logo are trade marks of Edwards Limited.
Maintenance
A652–07–880 Issue D
5.14
Fault finding
A list of fault conditions and their possible causes is provided here to assist in fault finding. If a fault cannot be
rectified when using this guide, call the nearest Edwards Service Centre for help.
5.14.1
The pump has failed to start
The electrical supply fuse has blown
The electrical supply voltage does not match that of the motor
The outlet pipeline or the oil mist filter is blocked
The oil temperature is below 12 °C
The oil is too viscous
The oil is contaminated
The pump has seized after long storage
The pump has been left to stand after contaminants have been pumped and has seized
The motor is faulty.
5.14.2
The pump has failed to achieve the specified performance (has failed to reach
ultimate vacuum)
The pressure measurement technique or gauge head is unsuitable or gives an incorrect indication of
pressure. For example, a contaminated Pirani gauge can indicate a pressure which is several times higher
than the actual pressure in the system.
The pump is filled with the wrong type of oil
There is a leak in the vacuum system
The oil level is low
The oil is contaminated
Vacuum fittings are dirty or damaged
The inlet catchpot is blocked
The pump has not warmed up.
5.14.3
The pump is noisy
The motor fan cover is damaged
The motor bearings are worn
The oil is contaminated with solid particles.
